According to Gram Research analysis, dietary supplements of thyme, gunnera, and liquorice powders significantly improved broiler chicken health at high altitude in a 2026 study of 500 birds. The herb-fed chickens showed 5-15% better weight gain and feed efficiency, healthier intestines with larger nutrient-absorbing structures, improved blood cholesterol and fat profiles, stronger antioxidant defenses, better heart function, and notably longer telomeres—the DNA protective caps that signal cellular youth—compared to control chickens eating regular feed.
Researchers tested whether three common herbs—thyme, gunnera, and liquorice—could help broiler chickens grow better and stay healthier when raised at high altitude where oxygen is lower. They gave 500 baby chickens either regular feed or feed mixed with these herbs and tracked their growth, heart function, and cellular health. The chickens that ate the herb-supplemented feed grew faster, had better digestion, healthier hearts, and even longer telomeres (the protective caps on DNA that signal cellular aging). This suggests natural herbs might be a simple way to boost chicken health without medications.
Key Statistics
A 2026 study of 500 broiler chickens found that dietary thyme, gunnera, and liquorice powders improved weight gain and feed conversion ratio by 5-15% compared to control feed, while also increasing intestinal villus height and absorptive surface area across all three sections of the small intestine.
According to research reviewed by Gram, herb-supplemented chickens in the 2026 trial showed elevated blood levels of protective antioxidants (nitric oxide and ferric-reducing antioxidant power) while harmful markers decreased, including 15-25% reductions in total cholesterol, LDL cholesterol, and triglycerides.
The 2026 study of 500 chickens demonstrated that dietary herbal supplements increased expression of antioxidant defense genes (SOD1 and glutathione peroxidase) while suppressing fat-producing genes (FAS and HMGCR) in the liver, suggesting herbs prevent metabolic dysfunction.
Chickens consuming thyme, gunnera, and liquorice powders in the 2026 research showed significantly longer telomeres in liver cells compared to control birds, indicating the herbs may slow cellular aging at the genetic level.
The Quick Take
- What they studied: Whether adding powdered thyme, gunnera, and liquorice to chicken feed improves growth, digestion, heart health, and cellular aging at high altitude
- Who participated: 500 one-day-old broiler chickens (Ross 308 breed) raised at 2,100 meters elevation in a high-altitude region
- Key finding: All three herbs improved weight gain and feed efficiency by 5-15%, enhanced intestinal health, reduced harmful cholesterol and fats, improved heart function markers, and increased telomere length (a sign of cellular youth) compared to chickens eating regular feed
- What it means for you: If you raise chickens or care about poultry farming, these affordable herbs could naturally improve bird health and productivity without antibiotics. However, results are specific to high-altitude conditions and broiler chickens—effects may differ in other settings
The Research Details
Researchers divided 500 baby chickens into five groups at a high-altitude farm. One group ate normal feed (the control), while four other groups ate the same feed mixed with different herb powders: thyme at 7.5 grams per kilogram of feed, gunnera at 7.5 grams per kilogram, and liquorice at either 3.75 or 7.5 grams per kilogram. The chickens were raised under identical conditions, and researchers measured their growth, how efficiently they converted feed to body weight, the health of their intestines, their blood chemistry, heart function using electrocardiograms (ECG), and even the length of telomeres in their liver cells.
This experimental design is called a controlled trial because it compares herb-supplemented groups directly against a control group that received no herbs. By keeping all other conditions the same, researchers could isolate the specific effects of each herb. The high-altitude setting was intentional—at 2,100 meters elevation, oxygen levels are lower, which naturally stresses chickens and makes it harder for them to grow well. Testing herbs in this challenging environment shows whether they can help animals cope with difficult conditions.
This research approach matters because it tests whether natural supplements can solve real farming problems. High-altitude chicken farming is common in many regions, but low oxygen reduces growth and increases disease risk. Rather than relying on antibiotics or synthetic drugs, this study explores whether affordable, plant-based alternatives work. The researchers measured multiple health markers—not just weight gain, but also intestinal structure, blood chemistry, heart function, and even cellular aging—giving a complete picture of how herbs affect overall health.
The study’s strengths include a large sample size (500 chickens), multiple treatment groups for comparison, and measurement of diverse health outcomes (growth, digestion, blood chemistry, heart function, and cellular aging). The researchers used standardized chicken breeds and controlled environmental conditions, which reduces confusing variables. However, the study was conducted in one specific high-altitude location with one chicken breed, so results may not apply to all farming conditions. The study was published in a peer-reviewed journal, meaning other experts reviewed the methods before publication. The main limitation is that this is a single study in chickens—results don’t automatically apply to other animals or to humans.
What the Results Show
All three herbs improved how well chickens grew and converted feed into body weight. Chickens eating herb-supplemented feed gained more weight and needed less feed to reach the same size compared to control chickens—a key measure of farming efficiency. The herbs also dramatically improved intestinal health: the finger-like structures in the intestines (called villi) that absorb nutrients became taller, wider, and had more surface area for absorption across all three sections of the small intestine (duodenum, jejunum, and ileum).
The herb supplements boosted the chickens’ natural antioxidant defenses—the body’s built-in system for fighting cellular damage. Blood tests showed higher levels of protective molecules like nitric oxide and antioxidant power, while harmful molecules like malondialdehyde decreased. The herbs also improved cholesterol and fat profiles: total cholesterol, harmful LDL cholesterol, and triglycerides (a type of blood fat) all decreased in herb-fed chickens.
At the genetic level, the herbs activated genes that produce antioxidant enzymes (SOD1 and glutathione peroxidase) while suppressing genes that produce excess fat in the liver. This means the herbs helped chickens build protective defenses while preventing unhealthy fat accumulation. Most remarkably, chickens eating herbs had longer telomeres—the protective DNA caps that shorten with age—suggesting the herbs may slow cellular aging.
Heart function improved in herb-fed chickens, shown by changes in electrocardiogram (ECG) wave patterns. Specifically, certain wave amplitudes decreased, which researchers interpret as improved cardiac function under high-altitude stress. The herbs also reduced the expression of genes responsible for making cholesterol and fat in the liver, suggesting they prevent metabolic dysfunction. These secondary findings paint a picture of herbs improving not just growth, but overall physiological health and resilience.
This research builds on growing evidence that plant-based supplements (called phytobiotics) can improve animal health without antibiotics. Previous studies have shown that thyme, gunnera, and liquorice contain beneficial compounds, but this is one of the first studies testing all three together in chickens at high altitude. The findings align with earlier research showing that herbal supplements improve intestinal health and antioxidant status, but the telomere-lengthening effect is a novel finding that suggests these herbs may have anti-aging properties at the cellular level. The results support the trend toward natural alternatives in animal agriculture.
This study was conducted in chickens at one specific high-altitude location, so results may not apply to chickens raised at sea level or in different climates. The study used only one chicken breed (Ross 308), so effects might differ in other breeds. The research doesn’t explain exactly which compounds in the herbs cause the benefits—it only shows that the whole powders work. Additionally, the study measured short-term effects (during the growth period), so long-term impacts are unknown. Finally, while results are promising for poultry, they don’t automatically apply to other animals or humans, though they suggest these herbs have biological activity worth investigating further.
The Bottom Line
For poultry farmers in high-altitude regions: Consider adding thyme powder (7.5 g/kg feed), gunnera powder (7.5 g/kg), or liquorice powder (3.75-7.5 g/kg) to chicken feed to improve growth, feed efficiency, and health markers. These herbs are affordable, natural, and showed consistent benefits across multiple health measures. Confidence level: Moderate to High for broiler chickens at high altitude; Lower for other conditions or species. For general consumers: This research supports the use of these herbs in poultry production, potentially leading to healthier chicken meat and eggs, though more research is needed on how benefits translate to human consumers.
Poultry farmers, especially those raising chickens at high altitude or in challenging environments, should care most about these findings. Agricultural researchers and veterinarians interested in natural alternatives to antibiotics will find this relevant. Consumers concerned about antibiotic use in food production may appreciate that these herbs offer a natural supplement option. However, this research is specific to broiler chickens—results don’t necessarily apply to egg-laying hens, other poultry, or other livestock. Humans should not assume these herbs will have identical effects in people without human studies.
In chickens, benefits appeared during the standard growth period (typically 6-7 weeks). Improved growth and feed efficiency would be noticeable within 2-3 weeks. Cellular changes like telomere lengthening likely occurred gradually throughout the study period. If these herbs were tested in humans, benefits would likely take weeks to months to appear, and more research would be needed to establish realistic timelines.
Frequently Asked Questions
Do herbal supplements really help chickens grow better at high altitude?
Yes, according to a 2026 study of 500 chickens, thyme, gunnera, and liquorice powders improved weight gain and feed efficiency by 5-15% at high altitude where oxygen is lower. The herbs also enhanced intestinal health and antioxidant defenses, suggesting they help chickens cope with altitude stress.
What specific health improvements did the herbs provide in chickens?
The 2026 research showed herbs improved intestinal structure (larger nutrient-absorbing villi), reduced harmful blood cholesterol and fats by 15-25%, boosted antioxidant defenses, improved heart function markers, and increased telomere length—a sign of cellular youth and reduced aging.
Are these herbs safe to use in chicken feed?
The 2026 study found no adverse effects from thyme (7.5 g/kg), gunnera (7.5 g/kg), or liquorice (3.75-7.5 g/kg) in broiler chicken feed. However, this research is specific to chickens at high altitude—safety in other species or conditions requires additional study.
Would these herbs have the same benefits in chickens raised at sea level?
Unknown. The 2026 study was conducted specifically at 2,100 meters altitude where low oxygen naturally stresses chickens. The herbs’ benefits may be partly due to helping chickens cope with altitude stress, so effects at sea level could differ and require separate testing.
Can humans get the same health benefits from these herbs as chickens did?
This 2026 study only tested chickens, so direct human benefits are unknown. While the herbs contain beneficial compounds, human studies would be needed to confirm whether people experience similar improvements in antioxidant status, cholesterol, or cellular aging.
Want to Apply This Research?
- If tracking poultry health: Log weekly weight gain, feed consumption, and feed conversion ratio (weight gained ÷ feed eaten). For farmers, track mortality rate, disease incidents, and medication use to see if herbs reduce these problems over time.
- For poultry farmers: Source high-quality thyme, gunnera, and liquorice powders; calculate the correct dosage for your flock size; mix into feed consistently; monitor chickens for improved growth and health over 3-4 weeks; adjust dosage if needed based on results.
- Establish baseline metrics before adding herbs (current weight gain, feed conversion, health issues). After 2-3 weeks on supplemented feed, compare new metrics to baseline. Track monthly for at least 8 weeks to see sustained benefits. Monitor for any adverse effects. Keep detailed records of herb source, dosage, and batch to identify what works best for your specific conditions.
This research was conducted in broiler chickens at high altitude and does not automatically apply to other poultry species, different environmental conditions, or humans. While the findings are promising for poultry farming, anyone considering using these herbs in animal feed should consult with a veterinarian or animal nutritionist to ensure appropriate dosing and safety for their specific situation. This article summarizes research findings and should not replace professional agricultural or veterinary advice. Results from animal studies do not guarantee identical effects in humans.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.